Wing type agitator

ABSTRACT

An agitator carriage is supported and powered for oscillatory movement along the length of an elongated vat, i.e. from end-to-end of the vat. A pair of stirring blades are supported from the carriage, one stirring blade depending into the vat from each side of the carriage. Each stirring blade is supported to move through a generally circular path in a vertical plane, and the blades are powered independently of the carriage drive. The stirring blade movement has both a vertical and horizontal component as it moves in the vat. The speed of movement of both the carriage and the blades can be varied, independently one from the other, so that the blades, as they move longitudinally of the vat, can be made to define, in the vertical planes of movement, loops varying from generally circular to smaller loops approaching a generally undulating path.

BACKGROUND OF THE INVENTION

This invention relates to processing equipment such as a cheeseprocessing vat and, more particularly, to an improved arrangement foragitating the process medium contained in the vat. The invention will bediscussed in connection with a cheese processing vat, specificallyprocessing cottage cheese, but it should be understood that it can beused to process various other media.

Various steps in the process of making cottage cheese are carried out ina process vat, e.g. curd cooking, washing, creaming, etc. Stirring ofthe product medium is required during various steps in the process, forexample the cooking step. It has been known to stir the creamed curdthrough the use of a traveling paddle assembly which moves through theprocess vat agitating the curd. Prior paddle assemblies have not beenentirely satisfactory. Among the reasons for their not having beencompletely satisfactory is that they did not completely agitate the curdin the vat because the stirring blades had only a limited verticalextension through the curd depth. This resulted in relatively quiescentareas of curd and incomplete stirring of the curd. For the most part,such prior paddle assemblies were of the pusher type with the stirringblades being pushed through the curd. Pusher blade assemblies encountersuch relatively large blade loads due to the pressure of curd thereonthat the blades must be small, e.g. have a limited vertical extension,to prevent damage and/or jamming of the blade assembly against the vatwall. Stirring paddle assemblies have also been used in the past,examples of these arrangements are found in U.S. Pats. 3,476,364 and3,490,751 both assigned to the assignee of this application.

This invention is concerned with the problem of achieving thoroughstirring of the process medium in the vat, and has among its generalobjects to provide an arrangement which effectively achieves suchstirring.

SUMMARY OF THE INVENTION

In accordance with this invention, one or more blade assemblies aresupported in a process vat from a movable carriage. The carriage movesrelative to the vat to propel the blade assembly, or assemblies, throughthe medium contained in the vat. The blades are further supported foroscillatory movement in a vertical direction, the arrangement preferablybeing such that the blades are driven through a generally circular pathin the vertical direction. Separate drive sources are provided for thecarriage and for moving the blades vertically and each drive source isindependently variable. By adjusting the speeds of the carriage and theblades, the blades can be set to define a series of loops in a verticalplane, as they are moved horizontally through the vat. The size of theloops (in a horizontal direction) can be varied by adjusting therelative speeds from a condition of relatively large loops throughdiminishing loop sizes approaching a generally smooth undulating path.The larger loops are preferred.

Other objects and advantages will be pointed out in, or be apparentfrom, the specification and claims, as will obvious modifications of theembodiments shown in the drawings, in which:

FIG. 1 is a side elevation, partially in section, of apparatus embodyingthis invention;

FIG. 2 is a top plan view of the carriage and agitator blade drive;

FIG. 3 is a side elevation, enlarged as compared to FIG. 1, of anagitator blade and its drive;

FIG. 4 is an end elevation, again enlarged as compared to FIG. 3, of theagitator blades and their drive;

FIG. 5 is an enlarged view of the pivotal connection of a blade to acrank arm;

FIG. 6 is an enlarged view of pivotal support assembly for the blade;

FIG. 7 is a side elevation of an alternative embodiment of thisinvention;

FIG. 8 is an end view of the embodiment of FIG. 7;

FIG. 9 is a section view taken generally along line 9--9 of FIG. 7;

FIG. 10 is a section view taken generally along line 10--10 of FIG. 7and illustrating an alternative blade pivot arrangement; and

FIG. 11 is a section view taken generally along line 11--11 of FIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the cottage cheese making process, process medium is pumped, orotherwise delivered, to a process vat 10 having side walls 12 and 14 andbottom wall 16. For best results, the process medium is continuouslystirred during some of the process steps. To achieve this stirring, acarriage 18 is supported on and moves along rail 20. Rail 20 extendslongitudinally over the vat. The carriage, by means of a suitable drivesystem (to be described hereinafter), is capable of traversingsubstantially the entire length of the vat by movement on the rail.Stirring blade assemblies 22 and 24 are suspended from carriage 18 andextend into vat 10, the paddle assemblies move longitudinally throughthe vat with the carriage.

Both stirring blade assemblies 22 and 24 are identical and thus only onewill be described in detail. The reference numerals used in describingone, 22, will be carried over to assembly 24 but with thedifferentiating letter "a" so that, if desired, the description ofassembly 22 can be read on assembly 24.

Blade 26 is attached to the lower end of elongated rod 28. The upper endof rod 28 is connected to crank arm 30 which is, in turn, fixed to shaft32 to be rotated by the shaft. A pivotal connection (see FIG. 5) isprovided between the rod crank arm by pin 34 extending between the crankarm and angle bracket 36 fixed to the top of rod 28.

As the crank arm rotates, the rod and correspondingly blade 26 areoscillated up and down. In operation, the blade will be oscillated inthe curd and in order to direct the blade through a definite path therod is supported intermediate its ends. More specifically, a fixedsupport assembly 38 includes a roller assembly 40 (see FIG. 6) having apivotal connection to fixed block 42 by pin 44. Block 42 is fixed in thesense that it does not move horizontally or vertically relative toeither the carriage or rod 28. Roller assembly 40 includes front andrear plates 46 and 48, pins 50 and 52 extending between the plates, androllers 54 and 56 journaled on the pins. Rollers 54 and 56 engage rod 28on diametrically opposite sides of the rod. Being engaged by supportassembly 38, rod 28 will assume a series of angular positions (two ofwhich are illustrated in FIGS. 1 and 3) causing blade 26 to move bothvertically and horizontally, i.e. the blade 26 will follow a generallycircular or elliptical path depending on the length of the crank arm.

The carriage includes a basic platform 58 and is supported on rail 20 byan arrangement of wheels 60 engaged between surfaces 62 and 64 providedon rail 20. The drives for both the carriage and the stirring bladeassemblies are supported on platform 58.

The drive for the stirring blades includes motor 68 and gear reducer 70connected by a V-belt drive 72. Shaft 74 extends from the gear reducerand is connected to shaft 32 by chain drive 76. Sheave 78 of the V-beltdrive is a variable diameter sheave; the diameter can be changed bymanipulating crank 80. By varying the diameter of sheave contact withbelt 82, the input to the gear reducer can be varied and thus the outputto the chain drive and shaft 32, will be varied accordingly. Theoperation and construction of the variable diameter sheave beingconventional and well known, no further description of it on the V-beltdrive will be made.

The drive for the carriage is similar to that for the stirring bladeassemblies and includes motor 84, V-belt drive 86, gear reducer 88, andchain drive 90 which drives shaft 92. A pair of wheels 60 are connectedon shaft 92 and the carriage is driven through that pair of wheels.Sheave 94 of the V-belt drive is a variable diameter sheave the same assheave 78 to permit adjustment of the carriage speed, therefore itsconstruction and operation will not be described.

Blocks 42 and 42a are supported on a horizontal channel 96, which issuspended from, but fixed to, carriage platform by vertical anglebrackets 98 and angle brackets 100. It is through this frame work thatsupport assemblies 38 and 38a are fixed relative to the carriage, andmove with the carriage.

Having described the construction and arrangement of the agitator, itsoperation will be described. First, it will be noted that crank arms 30and 30a are 180° out of phase and when blade assembly 28 is atbottom-dead-center blade assembly 28a is at top-dead-center. Withreference to FIG. 3, crank arm 30 rotated clockwise and this movementdraws the upper end of rod 28 up and to the left (as viewed in thedrawing) while the lower end of the rod is drawn up and to the right,support assembly 22 pivoting about pin 44 to accommodate this swingingaction of the rod. The lower end of the rod will follow a generallycounterclockwise path reaching top-dead-center, when the crank is at thetop of its movement, after which it will proceed down and to left (seeFIG. 1) and eventually return to its bottom-dead-center position (thefull line shown in FIG. 3). With the carriage stationary, the bladeassemblies, with this arrangement, will follow a generally elliptical,or circular path depending on the length of the rods and/or crank arms,oscillating in a vertical plane and achieving a positive stirring actionthrough the depth of the cottage cheese contained in the vat. Thestirring blade assembly oscillates horizontally as well as vertically asa result of its generally circular path. Thus, a thorough mixing throughthe depth of the process medium is achieved by positively displacingthat medium from the upper to the lower stratum, and vice versa, of themedium.

When the carriage drive is activated to move the blade assemblies thelength of the vat, the vertical oscillating movement of the assembliesis then coupled with horizontal travel through the vat. The thoroughvertical mixing is then achieved through the entire process mediumcontained in the vat. As illustrated in FIG. 1, this horizontal andvertical oscillatory movement of the blade assemblies causes theassemblies to describe a series of loops through the vat. Since thedrives for the blade assemblies and the carriage, are independentlyadjustable, these relative speeds can be adjusted to define eitherlarger or smaller loops or, if desired, to a path approaching agenerally smooth undulating path. Motor 84 is reversible and, through aconventional and well known arrangement, will automatically reverse whencarriage 18 reaches one end of its travel and propel the carriage backtoward the other end. As depicted in FIG. 1, the carriage is travelingto the right and when it reaches the dotted line position motor 84 willautomatically reverse and propel the paddle assemblies to the left. Thisis repeated at the left end and continues until the carriage motor isde-energized. This movement should be directly contrasted with prior artarrangements wherein the agitators moved horizontally, for example,either by stirring about a vertical axis or passing blades through themedium in a linear horizontal path.

As illustrated blades 26 and 26a are angled members in cross-section andeach extends across one-half the width of the vat. This insuresvirtually complete process medium engagement and the angular shapealternately lifts and pushes the medium as the blade oscillatesvertically. Other blade configurations can be used.

Blades 26 and 26a are supported to pivot about an axis generally normalto the direction of horizontal movement of the blade assemblies.

More specifically, blade 26 is provided with two brackets 100 and 102extending from the upper surface thereof and engaged on pivot pins 104and 106 which define the pivot axis for blade 26. In a conventionalmanner, pins 104 and 106 extend through clearance openings in thebrackets and inverted U-shaped blade bracket 108 are suitably anchoredto prevent withdrawal from those openings. Clearance is provided betweenthe lower ends of inverted U-shaped bracket 108 and the upper surface ofblade 26 to accommodate pivotal movement about pins 104 and 106 but withthe lower ends of bracket 108 providing a stop to limit that movement.With this arrangement, blade 26 is free to pivot as the blade assemblyis oscillated vertically and moved horizontally through the processmedium. For example, as the blade is moving from the full line positionin FIG. 3 to the dotted line position, it would actually pivot slightlyclockwise and, in contrast, as the blade assembly goes past itstop-dead-center position, the blade will pivot slightly in acounterclockwise direction as it moves down toward thebottom-dead-center position. This again contributes to the thoroughstirring action imparted to the process medium.

Reference will now be made to the FIGS. 7-9 for the description of analternative embodiment of this invention. In this embodiment, carriage18 (shown in block form) is again supported for horizontal movementalong track 20. Crank arm 110 is connected to and rotatable with shaft32. In this arrangement, the pivotal connection of support arm 112 tothe crank arm is made through a guide sleeve member 114, a subshaft 116fixed to crank arm 110 being engaged in circular hub 118. The guidesleeve member is part of an overall guide mechanism which includes thesleeve member and elongated rod 120. Rod 120 is supported on pivot shaft122 supported in a suitable bearing 124 fixed to support member 126depending from the carriage. Guide sleeve member 114 includes twocircular sleeve portions 128 and 130 which surround rod 120 and are freeto slide longitudinally along the rod. The guide sleeve member isconnected to support arm 112 by pins 132 and 134 extending from base 136of the guide sleeve member through holes 138 and 140 in the upperportion of support arm 112. A keeper member 142 has spaced portions 144and 146 which fit into apertures in pins 132 and 134 to fasten thesupport arm to the guide sleeve member. With this arrangement, as shaft32 is rotated in a clockwise direction, crank arm 110 rotates in asimilar direction and support arm 112 oscillates in a verticaldirection, swinging generally about the fixed pivot point 122 while thecarriage is moving the blade assembly horizontally.

More specifically, the assembly as illustrated in FIG. 7 shows thesupport arm just subsequent to its having to pass through itstop-dead-center position. The crank arm is pivoting in a clockwisemanner downward causing support arm 112 to also move downward with guidesleeve member sliding down on elongated rod 120 to accommodate thatmotion. During that rotation of the crank arm and sliding movement ofguide sleeve member 114, elongated rod 120 pivots in a clockwisedirection about pivot axis 122 to accommodate that motion. Accordingly,the blade assembly oscillates vertically while swinging, or pivoting,about the generally fixed axis 122 to produce the same type of motion aspreviously described in connection with the embodiment of FIGS. 1-6.

Again, the crank arm and the carriage are driven independently of eachother so as to regulate the looped path defined by the blade assembliesthrough the process medium. Also, a second blade assembly and drivemechanism identical to that illustrated in FIGS. 7, 8, and 9, isprovided on the opposite side of the carriage in the same manner asdiscussed in the embodiment of FIGS. 1-6.

Blade 150 is pivotally supported at the end of support arm 112 but in amanner different than that described in connection with the previousembodiment. With reference to FIGS. 10 and 11, the lower end of supportrod 112 is T-shaped having a cross member 152. One end 154 of the crossmember is journaled in a bearing block 156 fixed to the underside ofblade 150. The opposite end of the cross member 152 is provided with aretractable assembly to permit connection of the support arm to theblade. More particularly, an extension 158 fits over the end 160 of thecross member and includes a projection 162 which fits into opening 164in a second fixed block member 166. Spring 168 is seated against flange170 and bears on the end of extension 158. The extension 158 can bemoved to the left against spring 168 to free projection 162 from opening164 and permit the support arm to be disassembled from the blade. Withthis arrangement, the support arm can be connected to and disconnectedfrom the blade as desired.

Blade 150, identical to the blade in the previously discussedembodiment, is capable of pivoting about an axis which is generallynormal to the direction of horizontal movement of the blade assemblies.In this arrangement, pivotal movement of the blade 150 about that axisis limited by engagement between support arm 112 and the sides ofopening 172 through which the support arm extends. In order to reinforcethe blade at the point of engagement, blocks 174 and 176 are connectedto the underside of the blade.

Although this invention has been illustrated and described in connectionwith particular embodiments thereof, it will be apparent to thoseskilled in the art that various changes and modifications may be madetherein without departing from the spirit of the invention or from thescope of the appended claims.

I claim:
 1. Apparatus of the type described comprising, in combination,a vat having a bottom wall, spaced vertical side walls and an open top, a carriage, means supporting said carriage for horizontal movement relative to said vat generally parallel to said side walls, a stirring blade assembly extending through said open top into said vat, said stirring blade assembly including a blade member, means connecting said blade assembly to said carriage for horizontal movement therewith and for oscillating movement in a vertical plane relative to said carriage and said vat, said means connecting said blade assembly to said carriage includinga rotatable crank arm connected to and rotatably driven by said drive means for said blade assembly, an elongated support arm connected to said blade member, means pivotally connecting said support arm to said crank arm, and guide means connected to said support arm and said carriage and movable with said carriage, said guide means supported for pivotal movement about a horizontal axis while permitting sliding movement of said support arm relative thereto so that as said support arm is raised and lowered by said crank arm said support arm can also pivot in a vertical plane generally about the pivot axis of said guide means and oscillate in a horizontal direction, .Iadd. said guide means includingan elongated rod, means connecting said elongated rod for swinging movement about said horizontal axis, and sleeve means connected to said support arm and surrounding said elongated rod for sliding movement thereon, said sleeve means and said support arm oscillating vertically on said elongated rod as said crank arm is rotated with said elongated rod also swinging about said horizontal axis, .Iaddend. and drive means for moving said carriage horizontally relative to said vat and for oscillating said blade assembly vertically so that said carriage and said blade assembly can be moved horizontally through a process medium in said vat with said blade assembly also moving vertically.
 2. The combination of claim 1 wherein said means connecting said blade assembly to said carriage is operative to impart a generally circular movement to said blade assembly as said blade assembly is oscillated in said vertical plane.
 3. .[.The combination of claim 1 wherein said guide means comprises.]. .Iadd.Apparatus of the type described comprising, in combination,a vat having a bottom wall, spaced vertical side walls and an open top, a carriage, means supporting said carriage for horizontal movement relative to said vat generally parallel to said side walls, a stirring blade assembly extending through said open top into said vat, said stirring blade assembly including a blade member, means connecting said blade assembly to said carriage for horizontal movement therewith and for oscillating movement in a vertical plane relative to said carriage and said vat, said means connecting said blade assembly to said carriage includinga rotatable crank arm connected to and rotatably driven by said drive means for said blade assembly, an elongated support arm connected to said blade member, means pivotally connecting said support arm to said crank arm, and guide means connected to said support arm and said carriage and movable with said carriage, said guide means supported for pivotal movement about a horizontal axis while permitting sliding movement of said support arm relative thereto so that as said support arm is raised and lowered by said crank arm said support arm can also pivot in a vertical plane generally about the pivot axis of said guide means and oscillate in a horizontal direction, .Iaddend. said guide means comprising roller means engaging said support arm intermediate said blade member and the connection of said support arm to said crank arm, said guide means supporting said support arm for sliding movement of said support arm relative to said guide means and, during said sliding movement, said roller means maintaining continuous engagement with said support arm and pivoting about said axis, .Iadd. and drive means moving said carriage horizontally relative to said vat and for oscillating said blade assembly vertically so that said carriage and said blade assembly can be moved horizontally through a process medium in said vat with said blade assembly also moving vertically. .Iaddend.
 4. The combination of claim 3 wherein said carriage and blade assemblies have separate drive sources and each drive source is independently variable. .[.5. The combination of claim 1 wherein said guide means comprisesan elongated rod, means connecting said elongated rod for swinging movement about said horizontal axis, and sleeve means connected to said support arm and surrounding said elongated rod for sliding movement thereon, said sleeve means and said support arm oscillating vertically on said elongated rod as said crank arm is rotated with said elongated rod also swinging about said horizontal axis..].
 6. The combination of claim .[.5.]. .Iadd.1 .Iaddend.wherein said carriage and blade assemblies have separate drive sources and each drive source is independently variable. Apparatus of the type described comprising, in combination,an elongated vat having a bottom wall, spaced vertical side walls, closed ends, and an open top, means defining an elongated track above and extending generally parallel to the longitudinal axis of said vat, a carriage engaged on said track, first drive means for moving said carriage along said track, a blade assembly connected to said carriage for movement therewith and extending from said carriage through the open top of and into said vat, second drive means supported on said carriage for movement therewith and including a crank arm rotatable in a vertical plane, said blade assembly including an elongated support arm pivotally connected to and rotatable with said crank arm and a blade member connected to the portion of said support arm in said vat, and guide means connected to said carriage for movement therewith and having a generally fixed position relative to said carriage while being generally pivotable about a horizontal axis and engaging said support arm, said support arm connected for sliding movement relative to said guide means while pivoting about said horizontal axis as said support arm is driven by said crank arm, .Iadd. said guide means comprising,an elongated rod, means connecting said elongated rod for swinging movement about said horizontal axis, and sleeve means connected to said support arm and surrounding said elongated rod for sliding movement thereon, said sleeve means and said support arm oscillating vertically on said elongated rod as said crank arm is rotated and said elongated rod also swinging about said horizontal axis, .Iaddend. whereby said blade member is propelled through a process medium in said vat and oscillates vertically as well as horizontally.
 8. The combination of claim 7 wherein said first and second drive means are independently adjustable to vary the speed of said carriage independent of that of the oscillating movement of said blade member.
 9. .[.The combination of claim 8 wherein.]. .Iadd.Apparatus of the type described comprising, in combination,an elongated vat having a bottom wall, spaced vertical side walls, closed ends, and an open top, means defining an elongated track above and extending generally parallel to the longitudinal axis of said vat, a carriage engaged on said track, first drive means for moving said carriage along said track, a blade assembly connected to said carriage for movement therewith and extending from said carriage through the open top of and into said vat, second drive means supported on said carriage for movement therewith and including a crank arm rotatable in a vertical plane, said blade assembly including an elongated support arm pivotally connected to and rotatable with said crank arm and a blade member connected to the portion of said support arm in said vat, and guide means connected to said carriage for movement therewith and having a generally fixed position relative to said carriage while being generally pivotable about a horizontal axis and engaging said support arm, said support arm connected for sliding movement relative to said guide means while pivoting about said horizontal axis as said support arm is driven by said crank arm, .Iaddend. said guide means includes roller means engaging said support arm intermediate said blade member and the connection of said support arm to said crank arm, said guide arms supporting said support arm for sliding movement of said support arm relative to said guide means and, during said sliding movement, said roller means maintaining continuous engagement with said support arm and pivoting about said axis, .Iadd. whereby said blade member is propelled through a process medium in said vat and oscillates vertically as well as horizontally. .Iaddend. .[.10. The combination of claim 8 wherein said guide means comprisesan elongated rod, means connecting said elongated rod for swinging movement about said horizontal axis, and sleeve means connected to said support arm and surrounding said elongated rod for sliding movement thereon, said sleeve means and said support arm oscillating vertically on said elongated rod as said crank arm is rotated and said elongated rod also swinging about said horizontal axis..].
 11. The combination of claim 7 wherein said blade assembly depends from one side of said carriage and includinga second blade assembly connected to said carriage for movement therewith and extending from said carriage through the open top of and into said vat from the opposite side of said carriage, a second crank arm connected to said second drive means and rotatable in a vertical plane, said second blade assembly including a second elongated support arm pivotally connected to and rotatable with said second crank arm and a blade member connected to the portion of said second support arm in said vat, and second guide means connected to said carriage for movement therewith, said first and second guide means having a fixed position relative to said carriage, said guide means being pivotal about a horizontal axis and each engaging said first and second support arms intermediate the ends thereof with said support arms sliding relative to said guide means while pivoting about said horizontal axis as said support arms are driven by said crank arms, whereby said blade members are propelled through a process medium in said vat and move vertically as well as horizontally.
 12. The combination of claim 7 wherein said blade assembly depends from one side of said carriage and includinga second blade assembly connected to said carriage for movement therewith and extending from said carriage through the open top of and into said vat from the opposite side of said carriage, a second crank arm connected to said second drive means and rotatable in a vertical plane, said second blade assembly including a second elongated support arm pivotally connected to and rotatable with said second crank arm and a blade member connected to the portion of said second support arm in said vat, and second guide means connected to said carriage for movement therewith, said first and second guide means each comprisean elongated rod, means connecting said elongated rod for swinging movement abut said horizontal axis, and sleeve means connected to said support arm and surrounding said elongated rod for sliding movement thereon, said sleeve means and said support arm oscillating vertically on said elongated rod as said crank arm is rotated and said elongated rod also swinging about said horizontal axis, whereby said blade members are propelled through a process medium in said vat and move vertically as well as horizontally.
 13. The combination of claim 12 wherein said first and second drive means are independently adjustable to vary the speed of said carriage independent of that of the vertical oscillating movement of said first and second blade members.
 14. The combination of claim 12 wherein said blade assemblies each includea blade having a horizontal and a vertical extension, and means supporting said blade for pivotal movement about a horizontal axis generally normal to the direction of horizontal movement of said blade assembly.
 15. The combination of claim 7 wherein said blade assembly includesa blade having a horizontal and a vertical extension, and means supporting said blade for pivotal movement about a horizontal axis generally normal to the direction of horizontal movement of said blade assembly. 